Woven wire belt for paper making machines



July 5, 1938. H. G. sPEcHT WOVEN WIRE BELT FOR PAPER MAKING MACHINES Filed June 4, 1956 2 Sheets-Sheet l l i% i== E= =l sm aizig i INVENTOR HQERY SPEfHT BY M ATTORN EY July'5, 1938. SPECHT 2,122,592

WOVEN WIRE BELT FOR PAPER MAKING MACHINES Filed June 4, 1936 2 Sheets-Sheet 2 M a E mmnmmu. 1 ll:

i W'W pi muumum mfg-.15. TEQILL [11 .15.

INVENTOR HHI QW 6 SPEcH Q ATTORNEY Patented July 5, 1938 UNITED STATES WOVEN WIRE BELT FOR PAPER MAKING moms Harry G. Specht, Mon

mesne assignments,

tclair, N. J., assignor, by to Encor Corporation,

Belleville, N. J., a corporation of New Jersey Application June 4,

3 Claims.

The present invention relates to woven wire belts particularly for paper making machines of the Fourdrinier type. These belts are in the form of a continuous band of fine wire mesh which moves over spaced supporting rolls and in contact with suction boxes and rolls, and it is desirable to provide a wire which will have a relatively long wearing life. These wires are relatively expensive and in normal usehave an average life of about twenty days. The cost of changing a wire is great due to lost time in production, so that any increase in the wearing life of the wire is worth a great deal to the paper mills. Another desirable object is to provide a wire having a relatively smooth top surface for the forma'tion of the paper, so as to reduce wire marks as much .as possible, while at the same time providing the necessary porosity to permit the water to drain through.

The usual Fourdrinier wire is woven with circular cross-section warp and weft wires, and these not only provide a very small wearing surface at the under side but produce a noticeable mark in the paper. It is proposed in the present inven- 25 tion to provide the warp wires of square cross section, to the end that a larger wearing surface is provided which will remain uniform throughout a longer wearing life, and there is also provided a relatively smooth top surface, while at 30 the same time maintaining equal porosity for a given mesh and wire gauge as the usual type of woven wire having circular cross-section warp wires.

It is further proposed to utilize the sharp. cor- 35 ners of the square cross-section warp wires to cause the same to embed into the weft wires through the beating action of the reed, whereby the-tops of the weft knuckles are brought nearer to the top surface of the fabric, and the knuckles are more tightly interlocked to prevent sleaziness.

. With the above and other objects in view, em-

bodiments of the invention are shown in the acwill be hereinafter more fully described with reference thereto, and theinvention will be finally pointed out in the claims.

In the drawings:

a Fig. 1 is an enlarged plan view of a portion of a wire belt, according to one embodiment of the invention.

Fig. 2 is a longitudinal sectional view, taken along the line 2-2 of Hg. 1.

'55 Fig. 3 is a transverse sectional the line 3-3 ofFis. 1.

Fig. 4 is a greatly enlarged transverse section of a small section of the wire showing diagrammatically the comparative wearing surfaces of go the wire according to' the present invention and view taken along oompanying drawings, and these embodiments 1936, Serial No. 83,519 (01. 139-425) the usual wire having circular cross-section warp wires.

Fig. 5 is a plan view of a portion of a wire belt, having a twill weave according to a modified form of the invention.

Fig. 6 is a longitudinal sectional view, taken along the line 6-6 of Fig. 5.

Fig. 7 is a transverse sectional view, taken along the line l--'l of Fig. 5.

Figs. 8 to 17 are'longitudinalsectional views of further modifications in which modified form of weft wires are employed.

Fig. 18 is an elevation of a piece of twisted cable type weft wire as used in the modifications illustrated in Figs. 12 and 17. 1

Similar -reference characters indicate corresponding parts throughout the several figures of the drawings.

Referringto the drawings, and more particularly to Figs. 1 to 4, the Fourdrinier wire, according to the exemplary illustrated embodiment shown therein, comprises warp wires ll of square cross-section, and weft wires ll of circular crosssection, the upwardly bent knuckles of the warp wires providing the upper paper-formation surface and downwardly bent knuckles forming the lower wearing-surface.

In the weaving operation the reed hits the weft wires between the warp wires and through the square cross-section of the warp wires the edge of the latter bite into the weft wires, as at Il producing a ridge-like knuckle at-the underside, as at il the reed marks being indicated at li -I I. In practice the reed mark is produced at a point about 60 to 90 removed from that shown in Fig. 4, the tension applied to the warp, which is greater at one side of the shed than at the other side, causing the weft wire to turn about 60" to 90 bringing the reed mark to the underside of the fabric. It will be seen that the top weft knuckles II are thus brought closer tothe paper formation surface, and the bottom weft knuckles II" are brought closer to the wear surface, thus making for better paper'formation and longer life. Also the biting in of the warp wires with the weft wires interlocks them and prevents sleaziness. In the weaving ofa normally loose weave fabric, as for instance twill weave, this interlocking action is particularly effective in preventing the sleaziness which has heretofore been an objection to these weaves.

As seen in Fig. 4 the plane A--A represents the paper formation surface and the plane B,B the lower wearing surface. The dot-and-dash epresentation of round cross-section warp wir at I! illustrates the comparative cross-sectional area of round warp wires as compared to the square warp wires of the present invention. The wearing surface is increased to a very great extent at the beginning of wear, the wearing surface being 2 Y equal to the diameter of the round warp wire when half worn through. As is well knownthe round warp wires will wear very rapidly at the beginning of wear and when worn to a point where a relatively large wearing surface is provided are so thin that breakage is apt to occur. With the square warp wires of the present invention the wearing surface is not only uniform during the life of the wire but a large wearing surface is provided at the beginning of wear so that the thickness and strength of the warp wires is maintained for a relatively longer. period and breakage due to thinning of the knuckles is greatly reduced. Even when half worn through the knuckles have greater strength than the half worn through knuckles of the round cross-section warp wires due to their increased cross sectional area, so that breakage dueto excessive wear is practically eliminated. The depressed knuckles of the weft wire prevent wear upon' the warp knuckles to a point where the latter are actually worn through; whereas straight weft wires would permit the warp wires to wear through completely.

It has been estimated that the cross-sectional area of the square warp wires is approximately 28% greaterthan the round wires of the same gauge, and the increase in wearing life c-ver round wires is from 25% to 100%.

Considering the paper-formation side of the wire it will be seen that the distance between the centers of the round cross-section wires represented by the line I3 is considerably greater than the distance between the adjacent sides'of the square cross-section warp wires, represented by the line If, so that while the same porosity is maintained, a smoother and flatter paper-formation surface is provided, upon which the fibres of the paper stock will form better, due to their tendency to span the spaces between the wires rather than to be drawn down into them.

In Figs-5 and 6 I have shown a modification in which the wcven wire is of twill weave, the square cross-sectional warp wire l0 being woven ever wires into the weft wiresprevents the sleaziness usually present in twill weave wires.

. -.In Fig. 8 I have showna modificationin which both the warp wires l0 and the weft wires l 5 are of square cross-section, the warp wires being woven with the ordinary type of weave going over one and under one weft wire. This makes for increased wearing surface in the weft wires.

In Fig. 9 I have shown a modification in which the weft wires [6 are of rectangular cross-section, the longer dimension extending longitudinally of the cloth. This makes for a flatter weave and also increased wearing surface in theweft wires. In Fig. 16 I have shown the'weft wires fl of oval cross-section, the'long dimension extending longitudinally of the cloth. This also :makes for flatter weave and increased wearing surface in the weft wires.

. In Fig. 11 I have shown instead of single weft wires weft wires l -I8 of relatively small diameters, each pair being woven as a single weft.

This makes for a flat weave and increased wear= ing surface in the weft wires.

In Fig. 12 I have shown the use of twisted cable weft wires I9 the cable being preferably twisted from four strands. This type of weft lends itself te flatness of weave as it will be compressed at the knuckles, has better drainage characteristics as it can be brought closer to the paper formation surface it produces less wire mark.

In Figs. 13,14, 15, 16 and 17 I have respectively shown the square cross-section weft wires 1 5, the rectangular cross-section weft wires IS, the oval cross-section weft wires H, the double weft wires Ill-l8, and the twisted cable weft wires l9 woven into twill weave wire cloth, the warp wires going over one and under two of the weft wires.

It will be understood that the paper-making wire, according to my invention, may be employed either in the form of a belt en Fourdrinier machines, or as cylinder on cylinder machines, or in any other suitable manner.

I have illustrated and described preferred and satisfactory embodiments of the invention, but it will be obvious that changes may be made therein, within the spirit and scope thereof, as defined in the appended claims.

Having thus described my invention what I claim and desire to secure by Letters Patent is:-'

1. Woven wire fabric for paper making machines. comprising interwoven warp and weft wires with knuckles produced in both the warp and weft .wires, the warp wires throughout their length being of substantially square cross-section, the weft wires being of circular cross-section, the warp wires being embedded at their corners-in said weft wires by reed-produced blows on said weft wires 'whereby the weft knuckles extend between the side surfaces of said warp wires to bring said weft knuckles closer to the surface of the fabric and to lock the weft wires against twisting relatively to the warp wires, the lower warp'knuckles projecting substantially below the.

plane of the weft knuckles.

2. Woven wire fabric for paper making machines comprising interwoven warp and weft wires with knuckles produced in both the warp and weft wires, the warp wires throughout their length being of substantially square cross-section, and being embedded at their corners in said weft wires-by reed-produced blows on said weft wires,

whereby theweft knuckles extend between the I ried over fine and under a plurality of weft wires,

the warp wires throughout their length being of substantially square cross-section and being embedded at their corners in said weft wires by reed-produced blows on said weft wires, whereby the weft knuckles extend between the side surfaces of said warp wires to' bring said weft HARRY GESPECHT. 

